89 documents found, page 1 of 9

"Betão" de ultraelevado desempenho reforçado com fibras metálicas

In the scope of the PhD research of the first author, a greener UHPFRC was developed, using raw materials available in Portugal for rehabilitation/reinforcement applications. The new UHPFRC, besides incorporating lower quantities of cement and silica fume, included a national subproduct material from the oil industry. Several properties were evaluated: autogenous shrinkage, compressive strength, uniaxial tensil...

Multi-level study on UHPFRC incorporating ECat

The suitability of a recently developed ultra-high performance fibre reinforced cementitious composite (UHPFRC) incorporating Spent Equilibrium Catalyst, ECat, for structural applications is investigated through a systematic multi-level investigation across micro, meso and composite levels. Scanning electron microscopy, isothermal calorimetry, thermogravimetric analysis, and mercury intrusion porosimetry tests ...

Mechanical and Fracture Behaviour of an HPFRC

The current paper analyses the mechanical and fracture behaviour of a High-Performance Fibre Reinforced Concrete (HPFRC). An HPFRC was developed in a previous stage aiming to simultaneously, maximise aggregates content, achieve a compressive strength of 90120 MPa and maintaining self-compactability (SF1+VS2). The benefits of fibres hybridisation (using fibres with lengths of 13, 35 and 60 mm) on flexural streng...

Shear behaviour of RC-UHPFRC composite beams without transverse reinforcement

Strengthening existing reinforced concrete (RC) beams and slabs using a thin layer of ultra-high performance fibre reinforced cementitious composites (UHPFRC), plain (U) or reinforced (RU) with ordinary steel bars, has been shown to be a very effective way of increasing the flexural capacity in hogging moment regions. However, as the increase in the flexural strength can be very significant, the shear strength ...

Experimental investigation on punching shear behaviour of RC-(R)UHPFRC composit...

Strengthening existing reinforced concrete (RC) flat slabs by casting a thin layer of ultra-high performance fibre reinforced cementitious composite (UHPFRC) over the top surface constitutes an efficient solution for significant durability and flexural capacity enhancements. Previous research has shown that also the punching shear capacity can be substantially increased. However, the existing experimental evide...

Development of an extruder for laboratory testing of 3D printing mortars

Development of an HPFRC for Use in Flat Slabs

Fibre-reinforced cementitious materials represent one of the most significant developments in the field of concrete technology of the last decades. The improved performance of this new class of materials (in terms of workability, compressive strength, flexural/tensile behaviour and/or durability) allows rethinking several of the existing structural solutions. This paper describes research on high-performance fi...

Key Factors for Implementing Magnetic NDT Method on Thin UHPFRC Bridge Elements

This paper provides an overview of the use of the magnetic NDT method for estimating the fibre content, and fibre orientation and efficiency factors in thin UHPFRC elements/layers, along any two orthogonal directions. These parameters are of utmost importance for predicting the post-cracking tensile strength in the directions of interest. After establishing meaningful correlations at the lab-specimen scale, thi...

Self-compacting concrete also standing for sustainable circular concrete

Development of 3D printing sustainable mortars based on a bibliometric analysis

In construction, three-dimensional concrete printing technology is an innovative method that opens new design possibilities, reducing the construction time process. The incremental material deposition allows organic shapes without formwork, a mandatory constraint in preparatory phases of conventional complex concrete structures. Nowadays, in three-dimensional printing for construction industry, concrete is the ...